Understanding the Power of the Skin Modifier in Blender
Blender is undoubtedly a very powerful 3D application that features a wide range of tools. As a 3D modeler, there are many tools you'll probably be familiar with if you're coming from a different 3D application. In most programs you'll find the extrude command, subdivide, loop cuts and more. These tools all help you achieve the final 3D model that you want, and like most other applications there are powerful modifiers that let you do things like apply Boolean operations on your geometry.
However, there is one modifier in Blender that can greatly speed up the 3D modeling process, especially for creature and character design, which is the skin modifier. This one modifier can allow you to quickly rough out the base mesh for your character in a matter of minutes rather than hours.
In this article you'll learn about where this skin modifier can be used, and how it can benefit your workflow. We'll also run through a step-by-step video tutorial showing you how to setup your first base mesh using the skin modifier. If you want to jump straight to the video tutorial click here.
What Is the Skin Modifier?
If you've ever used the sculpting application, ZBrush, then you can think of the skin modifier a lot like Zspheres, because they work in a very similar way. You're essentially creating the basic shape of an object, and geometry will be built up around that. In Blender, you can basically extrude single edges, and apply the skin modifier to build up geometry around those edges. So you can essentially create a stick-figure person, apply a skin modifier and you'll get the basic model already there. You can add in more vertices, and fine tune it to get the shape looking how you want. The output is mostly quads; however there are some instances where triangles might appear around intersections.
Now, you can create complex shapes with the skin modifier, like fingers toes, etc. However, you can't really create fine details with it, which is why it's best to use it as a base mesh. You can then bring that base mesh into an application like Mudbox to add the finer details, or continue modeling in Blender.
Where to Use It
There are certainly different ways you can use the skin modifier, but the best is to generate base meshes for organic shapes like creatures, and characters. You can see from the image above you can quickly get the basic shape down of a character you want to model in just a few minutes.
You also have the ability to create an armature from the skeleton of your character, so each vertex acts as the joint for manipulation. This allows you to quickly pose your character without having to spend the time creating a complex rig.
Parameters to Understand
There are a few key parameters in the skin modifier that will be beneficial for you to have an understanding on when you're creating your own base mesh.
It's actually very easy to start building your base mesh, you can think of it as just drawing the basic shape. You can first drop in a simple plane, and with all the vertices selected, press Alt+M to open the merge option box and choose "at center" this will merge all the vertices on the plane into one single vertex. You can then use this single vertex to begin extruding the basic shape for your model.
Since the mesh is getting generated around the vertices and edges, as soon as you apply the skin modifier the underlying vertices will not be visible, which makes it very hard to select them. To change this, go to Edit Mode and make sure that clipping of hidden geometry is disabled in the 3D view. As soon as you do that, you should see the vertices are now visible, letting you easily select them.
There are two other modifiers that are crucial for using the skin modifier, and those are mirror modifier, and the subdivision surface modifier. By using the mirror modifier it will let you create one side of the mesh, and it will get mirrored across the selected axis. So if you're using the skin modifier to create a character, you only need to create one side of the character, and it will be mirrored over.
The subdivision modifier will add more geometry to the base mesh, smoothing things out, and letting you create smaller details like fingers and toes.
You'll also need to scale your vertices to alter the thickness of the skin modifier. You can do this by pressing Ctrl+A, this will let you uniformly scale each vertex. You can also press X or Y to scale it along the X or Y axis.
Let's dive a lot deeper into the Skin Modifier in Blender and walk you through step-by-step how to begin using it. In this video tutorial you'll learn how to setup a base mesh for a character using reference images. You'll also learn how to troubleshoot problems that can often occur when using the Skin Modifier, and you'll also learn techniques to ensure you're getting the best topology possible.
If you want to learn more about Blender and its capabilities be sure to check out our in-depth Blender tutorials in the Digital-Tutors Library.